Four-hour voiding observation with provocation test reveals significant abnormalities of bladder function in newborns with spinal dysraphism

Effectiveness of a voiding evaluation technique using a diaper equipped with a urination-activated alarm system to assess bladder function and voiding patterns in infants

PURPOSE

Four-hour voiding observation is a conventional method for evaluating bladder function in infants. However, it requires a diaper check every 5 min during the observation period, which creates an unusual environment for the infant, making the evaluation of natural urination difficult. This study aimed to investigate the parameters of urination before mature bladder function using a diaper equipped with a urination-activated alarm system.

METHODS

The study participants were 51 infants aged 0-4 years without bladder dysfunction. A urination-activated sensor was used to notify the inspector wirelessly when urination was detected, enabling the immediate assessment of ultrasonically measured residual urine. Bladder capacity was calculated as the sum of both residual urine volume and micturition volume, and the residual urine rate as the residual urine volume divided by bladder capacity.

RESULTS

A total of 36 boys and 15 girls were enrolled. The median (interquartile range) residual urine volume, bladder capacity, and residual urine rate were 3.0 mL (1.1-6.6), 53.0 mL (33.9-75.3), and 7.0% (2.1-15.0), respectively. Infants aged 0-1 and 2-4 years were then classified into Group A (N = 27) and Group B (N = 24), respectively. The residual urine rate was significantly higher in Group A (11.0% [5.4-21.2]) than in Group B (4.8% [0.6-8.9]; p < 0.01).

CONCLUSIONS

Voiding observation using a urination-activated alarm system allowed less invasive analysis in infants and revealed that the residual urine rate decreased with mature bladder function from about 2 years of age.

Asian guidelines for urinary tract infection in children

The followings are the level of evidence (LE) and grade of recommendation (GR) on pediatric UTI in Asia. Classification according to the sites of infection (lower versus upper tract), the number of episode (first versus recurrent), the severity (simple versus severe), or the existence of complicating factor (uncomplicated versus complicated) is useful to differentiate children with UTI whether they are at risk of renal damage or not (LE: 2, GR: B). Diagnosis of UTI requires both urinalysis that suggests infection and positive urine culture (LE:3, GR B). For pre-toilet trained children, urine specimen for culture should be collected by urethral catheterization or suprapubic aspiration. For toilet trained children, midstream clean catch urine is reliable (LE: 3, GR: A). Urine culture is considered positive if it demonstrates growth of a single bacterium with the following colony counts: (1) any growth by suprapubic aspiration, (2) >5 × 104 CFU/ml by urethral catheterization, or (3) >105 CFU/ml by midstream clean catch (LE:3, GR: B). For children with febrile UTI, renal and bladder ultrasonography (RBUS) should be routinely performed as soon as possible (LE: 3, GR: C). RBUS should be followed up 6 months later in children with acute pyelonephritis and/or VUR (LE: 3, GR: C). Acute DMSA scan can be performed when severe acute pyelonephritis or congenital hypodysplasia is noted on RBUS or when the diagnosis of UTI is in doubt by the clinical presentation (LE: 3, GR: C). Late DMSA scan (>6 months after the febrile UTI) can be performed in children with severe acute pyelonephritis, high-grade VUR, recurrent febrile UTIs, or abnormal renal parenchyma on the follow-up RBUS (LE: 3, GR: C). Top-down or bottom-up approach for febrile UTI is suggested for the diagnosis of VUR. For top-down approach, VCUG should not be performed routinely for children after the first febrile UTI. VCUG is indicated when abnormalities are apparent on either RBUS or DMSA scan or both (LE: 2, GR: B). VCUG is also suggested after a repeat febrile UTI (LE:2, GR: B). Appropriate antibiotic should be given immediately after urine specimen for culture has been obtained (LE:2, GR: A). Initiating therapy with oral or parenteral antibiotics is equally efficacious for children (>3 months) with uncomplicated UTI (LE: 2: GR: A). The choice of empirical antibiotic agents is guided by the expected pathogen and the local resistance patterns (LE: 2, GR: A). For children with febrile UTI, the total course of antibiotic therapy should be 7-14 days (LE: 2, GR: B). Circumcision may, but not definitively, reduce the risk of febrile UTI in males and breakthrough febrile UTI in males with VUR. Circumcision should be offered to uncircumcised boys with febrile UTI and VUR in countries where circumcision is accepted by the general population (LE: 3, GR: B), while in countries where childhood circumcision is rarely performed, other measures for febrile UTI/VUR should be the preferred choice (LE: 4, GR: C). Bladder bowel dysfunction (BBD) is one of the key factors of progression of renal scarring (LE: 2). Early recognition and management of BBD are important in prevention of UTI recurrence (LE:2, GR: A). Antibiotic prophylaxis to prevent recurrent febrile UTI is indicated in children with moderate to high grade (III-V) VUR (LE: 1b, GR: A). Surgical intervention may be used to treat VUR in the setting of recurrent febrile UTI because it has been shown to decrease the incidence of recurrent pyelonephritis (LE: 2, GR: B).